Asklemmy

Can’t you just bring a Trangia stove? They burn for EVER on half a litre of spirit.

Protein bars & Nuts. Lightweight, packed with nutrients / calories.

Canned food tends to be heavy for the amount of nutrients included.

MREs are great too, lots of variety. But, these things can plug you up pretty bad. The uh, gum, will help flush you out. Pretty bulky though.

Hardtack

You can dehydrate literally anything, and re-hydrate it on the trail with a little water and heat. Meats, Fruits, Vegetables, Soups, the works.

I highly recommend getting a gas burner, if you are comfortable with it. It’s great for cooking while camping. We’ve recently made tacos and risotto while camping. Also, depending on the brand/model, it works in most weather and you’re not reliant on gathering wood for a fire.

Nuts and dried fruit, granola bars, halva, canned beans in tomato sauce, canned meat and fish and other canned stuff, bread, all sorts of cheese, cucumbers, smoked meat were the staples of no-cooking-needed foodstuffs that keep for several days in the summer when I did hiking in my younger days. For breakfast, muesli with milk from powder. You can prep buckwheat overnight in cold water and eat it for lunch or breakfast. Onions and garlic to add taste, fresh herbs will keep just fine, too. Sun-dried tomatoes. Bell peppers.

Basically, you need to start thinking antique: what did travellers and adventurers eat several hundred years ago when refridgeration wasn't a thing?

Here's a list of some candidate foods, compiled from the experience of people who live in vans and other vehicles without refrigeration.

Beans

Why no boiled water? A small backpacking stove, something like a Pocket Rocket from MSR, is lightweight and can give you a very small, controlled flame that's hot enough to boil a liter of water in less than two minutes. And if you look around on Amazon, you can find them even cheaper than MSR, usually for less than $20. They connect to an isopropane canister which runs about $5.

Tortillas

Mcdonalds cheeseburgers. I saw a video of a guy doing the pacific trail with just a bag of hamburgers and he said they lasted well over a month. He also said its the best thing hes ever done as they gave him more strength than protein bars ever have. If i find it ill post.

Edit:I couldnt find the hamburger but i found mcdouble guy. I think 90 miles is still a few days worth.